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投稿时间:2016-05-23 修订日期:2016-07-26
投稿时间:2016-05-23 修订日期:2016-07-26
中文摘要: 通过背景误差协方差构建动力平衡约束是变分同化框架设计的重要环节。它不仅帮助实现变量间的协同分析,提高观测使用效率,还能改善变分极小化问题的性状。本文在系统梳理通过背景误差协方差引入动力平衡约束的方式、流程的基础上,对求解目前全球和有限区域变分同化系统普遍采用的准地转平衡和静力平衡约束的共性问题和存在的不足作了归纳总结。分析了求解准地转平衡约束的三类方案:动力平衡方程方案、统计方案和动力 统计相结合方案的优缺点。对照比较了不同垂直离散方案下求解静力平衡约束时遇到的欠定问题的表现以及解决途径。最后,展望了基于背景误差协方差构建动力平衡约束在赤道等特殊地区、高分辨率同化系统、以及集合 变分混合同化系统发展中面临的挑战和机遇。
中文关键词: 数值天气预报,变分同化,背景误差协方差,动力平衡约束
Abstract:Using background error covariance to construct dynamic balance constraints is very important to the design of variational assimilation schemes. It can permit a multivariate analysis, increase the value of each individual observation, and also improve the preconditioning of variational assimilation schemes. In this paper, the basic method and process of incorporating dynamic balance constraints are first surveyed.Based on this, the common problems of constructing the widely used quasi geostrophic and hydrostatic balance constraints in global and limited domain assimilation schemes are reviewed.Three constructing quasi geostrophic balance constraint methods are discussed, including dynamic balance equation method, statistical method, and dynamic statistical combined method.The undetermined problems of constructing hydrostatic balance constraint in different vertical grids and their solutions are also surveyed.Finally, the future challenges and opportunities of constructing dynamic balance constraints using background error covariance in special areas (such as tropics), in designing high resolution assimilation schemes and ensemble variation hybrid schemes are discussed.
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基金项目:中国气象局数值预报(GRAPES)发展专项和公益性行业(气象)科研专项(GYHY201506003)共同资助
引用文本:
王瑞春,龚建东,2016.变分同化框架通过背景误差协方差构建动力平衡约束的研究进展[J].气象,42(9):1033-1044.
WANG Ruichun,GONG Jiandong,2016.Review of Dynamic Balance Constraints Construction Using Background Error Covariance in Variational Assimilation Schemes[J].Meteor Mon,42(9):1033-1044.
王瑞春,龚建东,2016.变分同化框架通过背景误差协方差构建动力平衡约束的研究进展[J].气象,42(9):1033-1044.
WANG Ruichun,GONG Jiandong,2016.Review of Dynamic Balance Constraints Construction Using Background Error Covariance in Variational Assimilation Schemes[J].Meteor Mon,42(9):1033-1044.